[en] An intensive survey of planktonic larvae of Crassostrea gigas is conducted each summer by Ifremer to evaluate the seasonal reproduction dynamics of this economically important oyster species (French Velyger program). Automation of the identification and quantification of Pacific oyster larvae in the numerous samples collected in Arcachon bay was tested using an innovative approach, which combines the FlowCAM technology for digitisation of the particles and the Zoo/PhytoImage software for semiautomatic classification process. To target the oyster larvae in the highly-concentrated plankton samples, an original composite training set was elaborated: images of Bivalve larvae at different stages, coming from monospecific laboratory cultures, were added to images from natural samples representative of the in situ planktonic community at summertime. The obtained classifier was tested on a sampling site series for qualitative and quantitative comparison with the manual counting method by microscopic examination.
The preliminary results showed an efficient discrimination of targeted larvae from the other particles and from stage to stage, although inter-specific confusion was observed between larvae of the smallest size.
